Urethral redness, swelling and stinging are considered to be related to urethritis, urethral stone, urethral stenosis, prostatitis, vulvovaginitis and so on. 1. Urethritis: Urethritis is related to gonococcus, chlamydia trachomatis, mycoplasma infections and so on. The main symptoms of patients are urethral stinging, frequent urination, painful urination, abnormal urethral secretion, etc., which can be manifested as urethral redness, swelling and stinging pain. 2. Urethral calculi: the etiology is still unclear, and may be related to dietary habits, genetic factors, environmental factors and so on. Patients with urethral calculi may experience redness, swelling and stinging pain due to stone irritation or damage to the urethra, and are also prone to other symptoms such as difficulty in urination, dribbling urination, and incomplete urination. 3. Urethral stenosis: the disease is related to trauma, medical injury, infection, etc., the patient will have thinning of the urine line, prolonged urination, urinary dribbling, frequent urination, urinary urgency, dysuria and so on. Some patients with urethral stenosis will have urethral redness, swelling and stinging pain. 4. Prostatitis: male disease, mainly associated with pathogen infection, alcoholism, sedentary and so on. Typical symptoms of patients include pain in the suprapubic region, urinary urgency, urinary frequency, burning pain in the urethra, which may be manifested as urethral redness, swelling and stinging pain. 5. vulvovaginitis: female disease, disease and pathogen infection, long-term application of antibiotics and so on. Patients will appear localized skin and mucous membrane swelling, also easily accompanied by itching sensation, pain, burning sensation and so on. When complicated by urinary tract infections, frequent urination, urinary urgency, urinary pain and other symptoms, manifested as urethral redness, swelling and stinging pain. Urethral redness and stinging may also be caused by other factors, it is recommended that people with urethral redness and stinging go to the regular hospital in time for medical examination in order to clarify the cause of the disease and follow the doctor’s instructions for treatment.